Bag filling and weighing machine



May 3o, 1939.

J. M. LOW

BAG FILLING AND WEIGHING MACHINE Filed Aug. 19, 1936 6 Sheets-SheetI 1 May 30, 1939. J. M. Low

BAG FILLING lAND WEIGHING MACHINE v Filed Aug. 19, 1956 6 Sheets-Sheet 42 51 o 34 l 34:* l 33 49 84 .f2 99 A l 6o,

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May 30, 1939. 1 M Low 2,160,746

BAG FILLING AND WEIGHING MACHINE Filed Aug. 19, 19256 6 Sheets-Sheet 3 Umm May 3o, 1939.

J. M. Low 2,150,746

BAG FILLING AND WEIGHING MACHINE Filed Aug. 19, 1936 6 Sheets-Sheet 4 signup" May 30, 1939. J. M. LOW 2,160,746

BAG FILLING AND WEIGHING MACHINE Filed Aug. 19, 1936 6 Sheets-Sheet 5 "May 30, 1939. J. M. LOW

BAG FILLING AND WEIGHING MACHINE Filed Aug. 19, 1936 6 Sheets-Sheet 6 Patented May 30, 1939 UNITED STATES PATENT OFFICE 3 Claims.

I'he present invention relates to an automatic scale and bag filling machine of the type wherein a bag is attached to the machine and lled with bulk material with means for automatically weighing the bag as it is being filled with material and to stop the flow of material into the bag when the desired weight has been reached.

One of the objects of the invention is to construct such a machine that it will be inexpensive to construct, simple in operation and rugged in structure.

Another object of the invention is to construct such a machine which will be capable of handling many sizes of bags and flll the same with any desired weight of material, for instance from 100 to 200 pounds.

A further object of the invention is to provide a simple, although accurate, indicator to Warn the operator not only when the correct weight of material has been deposited but also one which will show if the feed valves have closed too quickly or too late causing short or heavy weights.

A still further object is to provide a bag clamping mechanism which insures that the mouth of the bag will be firmly held under the material discharge hopper regardless of the weight of material deposited and which may be readily operated to permit the filled bag to drop to the floor or onto a conveyor.

Another object is to so construct the bag clamping mechanism that it is readily operated by a foot treadle leaving the operators hands free for positioning the bag and operating the discharge valves.

A still further object is to construct such a machine that the scales forming an integral part of the machine that they are not subjected to any stress except their weighing function and with means for readily balancing the scales at all times and in which the weighing weights may be readily interchanged.

Another object is to provide a feeding valve mechanism composed of main and secondary 45 valves which are so arranged that the major portion of the material is controlled by the main valve which closes just prior to the time that the requisite weight has been dispensed, whereupon the secondary valve dribbles the remaining portion of the material until the total weight has been deposited.

In the drawings:

Fig. 1-side elevation of the machine from the left hand side.

Fig. 2--front view.

Fig. 3-side elevation from the right hand side.

Fig. 1 -enlarged rear view of Fig. 3, with the Weights removed.

Fig. 5-top plan view.

Fig. -enlarged detail View oi the valve mechanism.

Fig. '-enlarged detail, partly in section, taken on line 1*-1 of Fig. l.

Fig. S-plan view of the hopper support, partly in section.

Fig. 9--detail view of the scale beams.

A frame composed of four vertical corner angle bars, I, 2, 3 and 4 are attached at their lower ends to horizontal floor bars 5 and 6, and at their top edges by side bars I and 8. Front and rear tie bars also join the upper ends of the framing.

Intermediately aiiixed to the sides of the frames are further tie bars 9 and I0 which project beyond the rear frame bars 2 and 4 and are joined by transverse brace iron I I.

Pivoted to rear corner bar 2 is treadle lever I2 terminating in a dropped foot pedal I3. A second lever I4 is also pivoted to bar 2 and piv- 25 otally connected at its opposite ends to treadle lever I2 through link I5. The opposite ends of the link I5 are forked as indicated in the drawings, see Fig. 2.

An arm I6, pivoted at l1 to side bar 9, is connected at its rear end to lever I4 by pivoted lever bar I8. Carried adjacent the forward end of arm I6 is a roller I9. As clearly illustrated in Fig. 8, a horizontal rod 2D is attached to brace II by bearings 2I and 22 and flxedly attached to the left hand end of the rod is an arm 23 which extends toward the front of the machine and rests on roller I9. Also aflixed to the rod 20 are spaced apart bag clamp operating arms 24 and 25, whose forward ends are forked to provide pairs of spaced upright lingers 26, 21, 26 and 21'. These fingers raise and lower a split bag clamping ring 28 through contact with side loops 29 and 30 secured to opposite sides of the ring 28.

A dispensing hopper 3| is supported at opposite ends to scale beams 32 and 33. 'I'he supporting means for the hopper comprising open bottom brackets 34 and 34 secured below the side edge of the hopper and carrying blocks 35 and. 35' secured therein by bolts. The scale beams 32 and 33 carry cooperating knife edges 36 and 36 integrally fashioned on the ends of bolts 31 and 31'.

The scale beams 32 and 33 are pivoted intermediate their end on knife edges 38 and 38 integrally formed on center bolts 39 and 39'. The knife edges pivot on hardened bottom blocks 46 and 40 mounted in brackets 4| and 4| bolted to the rear members of the framing and thus support the weight of the hopper and bag to be filled.

At the rear of the side scale beams 32 and 33, there is provided a third set of knife edges 42 and 42 formed on the ends of the side bolts 43 and 43. Cooperating therewith is a transverse weight bar 44 over which weights 45 are hung. To prevent the weights from becoming displaced, a bar 46 is slipped through the slots 41 of the weights and this bar is secured by depending end brackets 48 and 48.

To initially balance the scale, the weights 45 are removed and the balance weight 49, slidably secured on bar 50 bolted to scale beam 33, is adjusted until the indicator pointer 5| secured to the extended end 52 of the scale beam 32 registers properly on the indicator lines 53 marked on the front of the frame member As shown in Fig. 9, transverse tie rods 54 are positioned on either side of the center pivots 39 and 39.

Mounted at the top of the frame and surrounding the ends thereof is a hollow platform 16 between the sides of which is mounted the material feed valve mechanism. Essentially, this mechanism consists of a front valve that is automatically opened and automatically closed when approximately the right amount of material has been fed to the hopper. A back valve is also employed which is manually opened and automatically closed as the material dispensed balances the weights for which the scale beams are set.

The valve mechanism is illustrated in detail in Figs. 1, 3, 5 and 6. Referring to these figures, it will be seen that the material is deposited into the inlet hopper secured at its ends by rivets 12 and 13 to side bars 14 and 14. The open bottom of the trough 1| is closed by two arcuate overlapping gate valves 15 and 16 which are swung on end rods 11 and 11 journalled through side bars 14 and 14', 1 and 8 respectively. As shown, the back valve 15 completely closes the open bottom of the inlet hopper and overlies a portion of front valve 16. n

Pivoted loosely to one side plate of back valve 15 is a trigger 18 having a notch 19 cut in its lower edge, to hold the valve open until it is automatically closed. A counterweight is placed on the free edge of the valve 15 to insure its positive closing. The extended end of the trigger lever is reenforced to provide extra weight as indicated at 6|. Normally, when the back valve 15 is closed, the trigger 18 rests on roller 82 carried on bracket post 83. However, when the gate 15 valve is opened, the notch 19 engages roller 82 and retains the valve in this position. Movement is given the valve through operating handle 84 pivoted on shaft 84' to the vertical frame member 3, see Fig. 3. This is accomplished through the side plate of valve 15, on the end opposite that to which the trigger 18 is pivoted, being provided with an offset roller 85 which rides on the curved cam surface 86 formed on the upper reach of operating lever 84.

If it is desired to manually trip the Valve 15 from the front of the machine this may be accomplished by depressing the end of rod ||6 pivoted at to raise the rear end H2, which in turn raises the trigger 18 and disengages the notch 19 from the roller 82.

The back gate 15 remains open during the bag filling operation due to the trigger notch 19 engaging roller 82 until the scale beams swing downward at the front of the machine and upward at the rear thereof. When this occurs, bolt head 61, threaded in upstanding bracket 63 secured to the rear of scale beam 32, pushes against the flat portion 8| of trigger 18 and trips the same, thus allowing the gate to gravitate to closed position.

Front valve operating rod 90, while loosely pivoted on the side of the hopper 1| is restrained in its movement by yoke 9|. A balancing counterweight 92, similar to valve weight 86, is attached to the outer edge of the front valve and the distance that the front valve covers the inlet hopper opening and its closing is adjustably regulated by means of screw handle 93 threaded through lug 94 bearing on upstanding arm 95 secured to the opposite side plate of the valve 16.

The front valve 16 is opened by contact of rod 96 with bolt 89 and is always in open position when the scale beams are pivoted downwardly by the weighting weights for the reason that this swings the front of the beams upwardly and allows bolt 89 to strike and raise rod 9U. After a bag has been positioned on the bag holder and back valve 15 opened the front valve begins to close for the reason that the material being fed to the bag overbalances the beams and removes support of the rod 96. The front valve gradual-L ly closes until it assumes the position shown in Fig. 6.

Initial balancing adjustment for the entire weighting and hopper assembly is realized through manipulation of the compensation Weight 96, slidably mounted on side rod 91. As disclosed in Figs. 1 and 5, the side balancing weight rod is secured at its rear end to bracket 98 carried on side braces 9, while its outer end1 free to contact and rest on rounded extension 52 of the scale beam 32.

To prevent undue vertical movement on the scale beams, adjustable bolts 99 and 99 carried on offset brackets |86 and |60 are positioned under the ends of the beams threaded into offset brackets and thus act as stops.

Referring to Figs. 2, 7 and 8, it will be observed that the hopper 3| terminates in a depending tubular section |6| having bayonet slots |62 cut in the lower edge thereof. Cooperating theren with is a ared bag holder |63 having lugs |64 attached to the upper section of the inner wall adapted to coact with bayonet slots |62. A locking pin |05 is frictionally held through registering openings formed in the overlapping portions of the hopper and bag holder.

It is preferable to cut away a hand hole |66 in the lower front edge of the bag holder to permit access to the contents of a bag being filled. As disclosed, the split bag clamping ring 26 binds around the greater portion of the flared bag holder and, in use, uniformly and snugly binds the bag to be filled around the holder.

In operation, the machine is positioned under a suitable source of material supply to insure that the supply will be deposited into upper valved inlet hopper 1|. The operator standing in front of the machine depresses foot treadle i3 which, through its associated linkage, raises pivoted bar I6 carrying offset roller I9, which in turn elevates contacting bar 23 to rotate shaft 26. Rotation of the shaft raises bag clamp operating arms 24 and 25 carrying the end forks to engage the offset handle members 29 and 30 attached to opposite sides of the split bag clamping ring 23,

which normally engages the flared bag holder |03. After the bag clamping ring 28 has been elevated, the operator positions an empty bag around the holder |03 and, relieves the pressure on the foot pedal, whereupon the ring 28 drops down and frictionally binds the bag mouth uniformly and smoothly around the holder.

After the bag is in position, the operator then grasps the back valve operating lever 8l and opens the same through contact of the upper cam surface portion of the handle engaging roller 85. The opening of the back valve carries the notched trigger 18 pivoted to the lower portion thereof outwardly until the roller 82 engages trigger notch 19 which maintains the valve in fully opened position and permits a rush of material through the valve into feed hopper 3 I. The hopper 3| is supported across the scale beams 32 and 33 and is pivoted thereto on opposite knife edges and, as shown in Fig. 6, the beams themselves are centrally supported across the frame on additional knife edges. As the weight increases in the suspended bag, the scale beams slowly rotate downwardly against the pull of the weighing weights 45 and just prior to the time when the total weight of material has been dispensed, the bolt head 81 at the rear of the beams pivots upwardly and strikes end portion 8| of the trigger 18 and thereby raises the notch 19 from engagement with the roller to permit the valve 16 to pivot to closed position under the influence of the valve Weight 80. As before described, the front Valve 16 closes gradually as the material is fed into the bag and overbalances the beam while the bag valve 15 swings closed, as hereinafter described, to overlie the front valve.

The front Valve 16 having been opened by contact of rod 90 with bolt 89 gradually closes as the bag is being lled, its open position having been determined by the adjusting screw 93 coming into contact with the upstanding arm 95. Back valve 15 closes to complete the weighing when the weights are balanced and the indicator pointer 5| registers with the levels 53 marked on the side frame I. If the valves have closed too quickly causing light weight, the indicator pointer will show this condition and, to secure the correct weight, the operator merely jiggles the operating handle 84 to permit a small amount of the material to drop through the back valve. On the other hand, if the indicator pointer shows that the valves have been sluggish in operation and too much material is deposited, the operator can readily reach through opening |06 and take out enough material to balance the beams.

After the correct weight of material has been placed in the bag, the operator again depresses the pedal I3 and the bag clamping ring being raised through the linkage mechanism, allows the filled bag to drop to the floor or conveyor.

Before an Ainitial run is made, it is necessary to place the machine in balance and accomplish this, all of the weighing weights are removed and the balance weight 39 moved along its slide rod until the indicator registers a true balance. The compensating weight 96 is adjusted so as to come to rest just prior to the scales balance, thereby allowing the scale beams to balance when the feed valves close.

What I claim is:

l. An automatic bag filling and weighing machine including a vertical frame, an open bottom feed trough positioned on the top of said frame, a pair of oppositely swinging valves pivoted on common pivots normally closing said open bottom, manually operated lever means for initially opening one of said Valves, pivoted scale beams attached to said frame below said feed trough, said beams initially opening the other of said valves, a bag holder secured to said scale beams, the bag held thereby adapted to receive material from said feed trough, and a trip device carried on said scale beams adapted to close one of said swinging valves when a predetermined amount of material has been deposited in said bag.

2. In an automatic bag filling and weighing machine a feed trough, a valved outlet for said trough, a weighing mechanism including pivoted beams to which a receptacle to be filled is attached, the outlet of said feed trough being controlled by two pivoted overlapping swinging valves, one of said valves being opened by movement of said scale beams when in non-weighing position, the other of said valves being opened by manual operation and closed by movement of said scale beams when in weighing position.

3. In an automatic bag filling and weighing machine, a feed trough, a valved material discharge outlet therefor, a weighing mechanism including spaced parallel pivoted beams, a hopper pivotally supported between said beams below said material discharge outlet, a receptacle to be filled detachably secured to said hopper, the said material discharge outlet being controlled by two pivoted overlapping swinging valves, one of which is opened by motion of the said beams in non-weighing position, while the other of said valves is opened by manual operation and closed by motion transmitted thereto by the said beams in weighing position.

JOHN M. LOW. 

